When a desired piece of music is to be selected from among those recorded on a CD for reproduction on a CD player, the music is selected generally by manipulating the operation panel on the body of the CD player to give a track skip command, or by manipulating some of the number entry keys on a remote control unit and thereby directly specifying the track number of the desired music.
Such a selection-reproduction system is relatively easy for the adult to use but is difficult for the infant to manipulate.
Further CD players are adapted for various special reproduction operations including an introduction reproducing operation to successively reproduce only the beginning portions of the pieces of music on the CD, each for several seconds, a random reproduction operation to reproduce all the pieces of music on the CD randomly, and a repeat reproduction operation to repeatedly reproduce all the pieces of music on the CD or the specified one of them. In this case, an increase in the number of operation buttons or in the number of manipulation procedures makes the player more difficult to use for the infant.